Railway car roll dampening friction device

ABSTRACT

An energy-absorber for swaying motion between the body and sideframe portions of a railroad car has a housing and a fulcrum adapted for mounting on the same portion of the car and has a lever pivoted on the fulcrum and adapted for sliding engagement with the other portion of the car. The housing contains a friction shoe having inclined wedging surfaces at its opposite ends and inner and outer wedge members having inclined surfaces mating with those of the shoe. The drive rod of the energyabsorber is pivoted to the operating lever and has an abutment engaging the outer wedge and has a compression spring around its inner end engaging the inner wedge. A spring of greater capacity in the housing produces friction increasing with the insertion of the rod and the shoe into the housing. Structure for providing maintenance-free operation over long periods of use is described.

United States Patent FRICTION DEVICE [76] Inventor: Carl E. Tack, 157Linden St.,

Elmhurst, 111. 60126 [22] Filed: Jan. 5, 1973 [21] Appl. No.: 321,236

Related U.S. Application Data [63] Continuation-impart of Ser. No.6,473, Jan. 28,

1970, Pat. No. 3,731,638.

[52] U.S. Cl 105/199 A, 105/199 CB, 105/453, 267/9 A, 267/9 C, 308/138[51] Int. B6lf 5/14, B61f 5/24, F16c 17/04 [58] Field of Search..105/197 D, 197 R, 199 A, 105/199 C; 199 CB, 199 F, 199 R, 105/453;267/9 A, 9 C; 308/138 [56] References Cited UNITED STATES PATENTS1,347,898 7/1920 Eaton 105/199 R 2,497,829 2/1950 Baselt 267/9 C2,574,788 11/1951 Janeway et a1 t 267/9 C 2,844,366 7/1958 Butterfield267/9 C X 2,961,974 11/1960 Seelig, Jr. 105/453 X 3,043,241 7/1962Ortner 105/199 CB 3,439,631 4/1969 Cope 105/199 R X Tack 1 Mar. 5, 1974[5 1 RAILWAY CAR ROLL DAMPENING 3,514,169 5 1970 MacDonncll 308/1383,731,638 5/1973 Tack 105 199 A Primary ExaminerRobert G. SheridanAssistant ExaminerHoward Beltran Attorney, Agent, or Firm-Gary,Juettner, Pigott &

Cullinan [57] ABSTRACT An energy-absorber for swaying motion between thebody and side-frame portions of a railroad car has a housing and afulcrum adapted for mounting on the same portion of the car and has alever pivoted on the fulcrum and adapted for sliding engagement with theother portion of the car. The housing contains a friction shoe havinginclined wedg ing surfaces at-its opposite ends and inner and outerwedge members having inclined surfaces mating with those of the shoe.The drive rod of the energy-absorber is pivoted to the operating leverand has an abutment engaging the outer wedge and has a compressionspring around its inner end engaging the inner wedge. A spring ofgreater capacity in the housing produces friction increasing with theinsertion of the rod and the shoe into the housing. Structure forproviding maintenance-free operation over long periods of use isdescribed.

7 Claims, 14 Drawing Figures RAILWAY CAR ROLL DAMPENING FRICTION DEVICEThis is a continuation-in-part of an application of the same inventorfiled Jan. 28, 1970, Ser. No. 6,473, now

U.S. Pat. No. 3,731,638 issued May 8, 1973.

This invention relates to energy-absorption devices for railroad cars,and more particularly to a friction strut or frictional energy absorberfor application to a freight car to permit high speed operation thereofwithout the problems of derailment, particularly on curves, limiting theoperating speed before the invention.

In the interest of brevity, there are omitted from this applicationcertain aspects of the fuller discussion of region 'of normalcompression and, in addition, provides means to disable the energyabsorber during return motion occurring immediately after separativemotion substantially faster than the body-oscillation motion whichoccurs at critical car speed. As more fully discussed in'the co-pendingapplication, the latter feature of operation permits rapid downward andreturn motions of the wheels at crossings and the like without transferof shock to the body which would result if all approach motions of theside-frame and the body were opposed without discriminationtherebetween.

The invention will best be understood, both generally and in detail,from consideration of the embodiments thereof illustrated in the annexeddrawing, in which:

FIG. 1 is a more or less schematic fragmentary eleva-v tion view of africtional energy-absorbing device of the invention mounted on a carbody and slidingly engaged with the side frame of thetruck;

FIG. 2 is a vertical sectional view of a frictional energy-absorbingdevice embodying certain aspects of the invention;

FIG. 3 is a horizontal sectional view taken along the line 3--3 of FIG.2;

FIG. 4 is a fragmentary view, partially in section and partially inelevation, of an improved embodiment of the invention;

FIG. 5 is a sectional view similar to the section of FIG. 4, but showingan altered position of the parts;

FIG. 6 is'a top plan view of the upper of two wedge members shown inFIGS. 4 and 5;

FIG. 7 is a sectional view of the wedge member taken along the line 77of FIG. 6; 7

FIG. 8 is a view partially in elevation and partially in section takenalong the line 8-8 of FIG. 4 in the direction indicated by arrows, withcertain parts shown in elevation successively broken away in section forclarification of the relationship of the parts;

FIG. 9 is a top plan view of the lower of the wedges shown in FIGS. 4and 5;

FIG. 10 is a side elevational view of the wedge of FIG. 9;

FIG. 11 is a sectional view along the line 11-11 of FIG. 5 in thedirection indicated by arrows;

FIG. 12 is a sectional view along the line l2--12 of FIG. 5 in thedirection indicated by arrows;

FIG. 13 is an angled or offset sectional view along the line l3l3 ofFIG. 11; and

FIG. 14 is an enlarged fragmentary sectional view correspondinggenerally to a portion of FIG. 11 or 12, but showing the effect ofwear-in of certain of the parts.

The illustration of FIG. 1 shows one manner of mounting anenergy-absorbing device of the invention on a railroad car (four beingnormally employed but only one being shown) for the purposes set forthin the co-pending application earlier mentioned. The energyabsorbingdevice, generally designated 10, is mounted by. brackets 12 to a web 14associated with the body bolster and extending across the lower portionof the end of the car body (not shown). A drive rod or actuator 16 ofthe energy-absorber l0 depends downwardly and its lower end is pivotallyattached at 18 to the outer end of a lever or crank 20, the opposite endof which is pivoted at 22 on suitable ears 24 depending from the shearpanel portion 26 of the body bolster assembly. The ears 24 thusconstitute a fulcrum for the lever or crank 20. The crank 20 is insliding engagement with a bearing plate 28 on the upper surface of thesideframe 30 of the car, upon which the wheels 32 are mounted inconventional fashion. The conventional spring-mounted truck bolster andpivotal mounting thereon of the body bolster are omitted from thedrawing, the showing thereof being superfluous to understanding of thepresent invention.

The internal construction of the energy-absorbing device is shown inFIGS. 2 and 3. The housing or casing is formed by four corner-anglemembers 34. In the lower region, these are joined, preferably bywelding, to four internal plates 36, which thus enclose the lowerportion of the housing and also serve as friction surfaces as laterdescribed. At the top, the-angle members 34 are welded to an internallyseated end cap 38 having a central aperture 40.

Loosely surrounding the rod or shaft 16 are upper and lower wedges orwedge rings 42 and 44. Each wedge has a central aperture 46 of tapereddiameter, being largest at the adjacent or facing surfaces and smallestat the opposite surfaces, but passing the rod 16 freely and loosely atall points to accommodate the slightly arcuate motion of the lower endof rod 16 to be later described. The periphery of each wedge ring isgenerally square and each wedge has the general outer shape of atruncated pyramid having minimum dimensions in the inner or facingregion and maximum dimensions in the opposite region.

' Between the wedge surfaces of the rings 42 and 44 are disposedfriction shoes 48, each of an L-shaped horizontal cross-section havingthe outer surface of one arm in sliding engagement with one of theplates 36 and the outer surface of the other arm in sliding engagementwith an adjacent plate 36. The upper and lower end portions of the shoes48 are internally inclined in correspondence with the inclination of thewedge rings, which are in contact therewith only at the orthogonalfaces, the comers of the pyramidal wedges being bevelled at 49 to avoidcontact with the internal corner portions of the shoes 48. A flange orcollar 50 on the external lower portion of the rod 16 constitutes anabutment engaging the outer surface of the lower ring 44, with asuitable washer 52 interposed. A coiled spring 54 surrounds the inner orupper end of the rod 16 and is compressed between the surface of theupper wedge ring 42 and a disk flange or washer 56, which is adjustablypositioned by a nut 58 on the threaded inner or upper end of the rod 16.

A coiled spring 60, of much larger restoring-force or capacity than thespring 54, surrounds the entire upper portion of the movable assemblyjust described, being normally under relatively small compressionbetween the end cap 38 and the radially outer portion of the upper wedgering 42. The latter is formed with a rib 62 separating the radiallyinner seating of the end of the spring 54 from the radially outerseating of the surrounding heavier spring 60.

The energy-absorption characteristics of the construction shown in FIGS.2 and 3, which may be called a friction strut, may be understood fromconsideration of the above-described construction. The moving portion ofthe assembly (the rod 16, the wedges 42 and 44 and the shoes 48) slidesin the housing against a frictional force determined by the lateralforce spreading apart the shoes 48, which is in turn determined by themagnitude of the spring forces urging the wedge rings 42 and 44together. A minimum or biasing force is provided by the small spring 54.This spring exerts no longitudinal force urging the rod 16 in eitherdirection, and the lateral force exerted on the shoes 48 by this springmay be considered more or less uniform at all times.

The larger spring 60 serves a dual purpose, both biasing the entiremovable assembly outward and exercising variable control of thefrictional resistance to motion. The friction established by the lightbiasing spring 54 is relatively small and is normally effectiveprimarily when the rod 16 is in a wholly extended position, i.e., withthe spring 60 under substantially no compression and no inward forceexerted at the outer-end pivot point 18. The position assumed by the rod16 in this condition may be determined by the adjustment of the nut 58,which is usually adjusted to sufficient tightness so that lifting of thelever from engagement with the side-frame which normally supports itdoes not produce removal of the shoes 48 from the housing. A pin orsimilar stop-member (not shown) is normally inserted across the housingat the outer end to limit the outward motion and thus facilitateassembly as well as permit adjustment of the nut 58 to be made withoutrestriction to such a minimum friction requirement if it is desired tomake the first portion of an inward stroke of the rod 16 essentiallyentirely frictionless. If so desired, the adjustment of the nut 58 canbe used as a trimming adjustment, to provide a pre-establishedfrictional damping or opposing force to inward motion of the rod 16 atany predetermined inward position.

The motions and forces produced by the energyabsorbers of the inventionin the coupling between the body and the side frames will now be brieflydescribed, omitting certain more detailed explanation of the purposesserved and advantages obtained in operation of a railroad car whichappears in the earliermentioned co-pending application. As alreadyindicated, the lowermost portion of the crank is in frictional slidingcontact on the bearing plate 28 atop the side frame 30 leaving the truckfree for pivotal motion at curves without the use of universal joints orany similar constructions introducing problems of complexity andmechanical failure. The energy-absorbers 10 are installed at a heightsuch that with the car stationary on a level track, the rod 16 is drivenby the weight of the car body part-way into the housing. The degree ofpen etration in this median or normal position will of course varysomewhat with the weight of the load in the car. It is of coursepossible to match a particular detailed description or adjustment to thecar each time it is loaded (or emptied) but the mode of operation is toa large extent self-compensating for degree of loading because ofinertia change. In this normal or median position, the compression ofthe large spring 60 is relatively small as compared with the degree ofcompression which occurs on alternate sides upon the occurrence ofrocking relative motion between the body and the side frames.

When rocking motion occurs on a straight track, damping action occursalternately on one side of the car and then the other. As the rod isdriven into the housing, the pressure of the spring 60 on the wedgerings 42 and 44 increases, thus increasing the friction between theshoes 48 and the plates 36 to dissipate oscillation energy of thesprings of the car (not shown). However, this frictional dissipation isessentially unidirectional. When the motion reverses, i.e., as the carbody and the side frame commence to separate, the spring 60 forces therod 16 outward. Obviously, the energy-absorber 10 presents no frictionalresistance to this separative motion. On straight uninterrupted track inwell-maintained condition, cranks 20 on both sides of the car are at alltimes in contact with their corresponding side-frame plates 28. However,in the event of relatively large separative excursions, the rod 16 mayreach the outer limit of its travel before the separative motion ends,in which event contact between the crank 20 and plate 28 may be broken,until the motion is arrested by the action of the absorber on theoppsite side, and then again reestablished to commence the compressionof the spring 60. Such a departure from contact also occurs for a shorttime in the event a downward wheel excursion, even though of smallmagnitude, is too fast to be followed by the lever as now to bediscussed.

Despite its effectiveness in damping car body oscillations, theenergy-absorber of the invention produces a minimum of interference withthe action of the car springs in isolating the car body from impact-typerapid excursions of the wheels such as at crossings, sudden clips atvery soft joints, etc., and in high-speed operation on rough track.Although the release of friction within the damping device and outwardreturn of the actuator rod are sufficiently fast so that swaying of thecar (except of very large magnitude) does not produce disengagement ofthe crank or lever 20 from the bearing plate 28, small downwardexcursions and returns of the wheels, if sufficiently fast, are notfollowed due to the finite time required for release of friction withinthe damping device at the instant when the side frame suddenly dropsdown and also the minimum friction established by the bias spring 54,which limit the speed of ejection of the rod and the shoe. The greaterthe compression of the spring 60 at the time of such an occurrence, thegreater the time lag before the lever 20 is able to follow such a rapiddownward motion. Accordingly, the rapid upward return of the wheelsproduces minimal jarring of the load even when (as is uncommon) such atrack discontinuity is encountered at an instant when the frictionalforce within the damping device is very high. The minimum friction isdesirably adjusted (or may less advantageously be fixed by suitableprecise selection of the larger springs, if bias springs are omitted) sothat moderatly large body oscillations are wholly followed at the carscritical speed but separative motions occurring very much faster thanthis at either side quickly break the contact.

I An improved embodiment of the energy-aborber or friction strut of theinvention is shown in FIGS. 4 through 14, in which portions or elementswhich are substantially identical with the embodiment already describedbear the same reference characters. Portions of the assembly are alteredin a manner found to greatly improve smooth and maintenance-freeoperation over long periods of use.

The external corners of the upper and lower wedges 64 and 66 and thecorresponding portions of the shoes 68 are differently shaped andrelated than in the embodiment of FIGS. 2 and 3. As already indicated,in that embodiment clearance is provided at the internal angles of theL-shaped shoes, all contact between the wedges and the shoes being alongorthogonal interfaces excluding the corners. It will be noted that withthis construction, i.e., with sufficient of the pyramidal corners of thewedges bevelled away to avoid all contact with the internal corner of ashoe, both the internal shaping of the .corner of the shoe and the shapeof the mentioned bevel are unimportant. In the embodiment of FIGS. 2 and3, the internal corner or angle of each L-shaped shoe is merely formedwith a convenient arbitrary degree of roundness and the corner bevels 49on the wedges are likewise more or less arbitrarily determined, subjectonly-to the limitation of having suffi-' cient corner-removal in allhorizontal planes to avoid contact with the rounded internal corner ofthe shoe. Thus in the illustration of FIG. 3, it will be seen that thebevelled corners 49 of the wedge form planes of an inclination producinggreater bevel width with increasing horizontal dimension, the slope ofthe plane of the bevel being more or less arbitrarily selected.

The improved embodiment employs a substantially different relationbetween the external corners of the pyramidal wedges and the internalcorners of the L- shaped shoes (i.e., the end portions of the shoeswhich receive the oppositely disposed wedges). The construction of FIGS.2 and 3 is found to require great precision of matching of the abuttingsurfaces of the wedge and the shoe, respectively, to produce andmaintain the desired smooth and troublefree operation. Any roughness ordeviation from smooth and exact correspondence between the internalhalf-pyramidal shape of the end of the shoe and the external pyramidalshape of the wedge fitting therein except at the corners is found toproduce jamming and locking.

In theory, such effects may be avoided by sufficiently high precision inmanufacture, but this is difiicult as a practical matter. As a result,the construction of FIGS. 2 and 3 in practice requires a prolongedperiod of break-in, either installed on a railroad car or withartificial simulation of the action thereof, before operation is fullyreliable. In such break-in, it is normally found necessary tooccasionally free the device from a jammed or locked condition, whichoccurs with decreasing frequency as use continues until reliably smoothoperation is'ultimately obtained when wear on the parts finally producesexact mating.

The difficulty in producing this smooth mated condition withoutprohibitive precision in manufacture, and without extended break-induring which jamming and locking may occur, it avoided by the improvedconstruction.

In essence, the construction of FIGS. 4 to 14 provides what might betermined a temporary or short-term manner of cooperation of the partswhich gives fully satisfactory maintenance-free operation during abreaking-in period which is not externally observable as a distinctperformance phase but produces a transition to a final or longterm modeof operation which is not only equivalent to, but indeed somewhatsuperior to, the long-term operation obtainable only after a longbreak-in period involving freeing of occasional jamming with theconstruction previously described.

In the wedges 64 and 66 of the improved construction, the bevelledplanar corner surfaces 70 which separate the inclined planar sides 72are mated to corre sponding inclined planar surfaces 74 in the angles ofthe L-shaped shoes 68. Both the external corner surfaces 70 on thewedges and the internal corner surfaces 74 on the shoes are rectangular,i.e., of equal width along their length. As best seen in FIGS. 11 and12, in the as-manufactured condition, the internal corner surfaces 74 ofthe shoes are slightly wider than the external corner surfaces 70 on thewedges. The effect of this is that in the as-manufactured condition,contact between the shoes and the wedges is solely at the corners, thearms of the L-shaped shoes being substantially entirelyout of contactwith the sides 72 of the wedges in this condition. The force on theshoes producing friction with the plates 36 is thus exertedsubstantially solely at the corners, but is distributed between theorthogonal components into which this force is inherently resolved inproducing the friction. The application of the wedging action at onlythe two diagonally opposite corners, rather than at the four sides of asquare, eliminates the primary cause of problems with jamming during theperiod of break-in. 7

As use progresses, the difference in width of the wedging surfaces atthe diagonally disposed interfaces is gradually reduced until there isultimately reached the condition of abutment of all of the matingsurfaces, both at the four sides and at the'diagonally opposite corners,as shown in the enlarged view of FIG. 14, showing an exemplary pair ofadjacent wedging interfaces. To prevent any possible binding, grooves 75(seen only in the enlarged FIG. 14) are formed at opposite edges of thecorner surfaces of shoes 74. After the break-in period, all of themating surfaces thus cooperate in the wedging action. In addition to theadvantage regarding elimination of malfunction, and thus fullypracticable usability during break-in, the already-long useful life ofthe device is further extended by the longterm utilization of the cornerportions in the wedging action, as compared to the previously describedconstruction wherein the corners are not utilized. it will be noted(best seen in FIG. 12) that in the regions where the cross-section ofthe wedges is small, and the cross section of the shoes correspondinglylarge, the added contribution of the corner portions to the wedgingaction is major.

The improved embodiment also differs from the one earlier described inthe construction by which the drive rod 76,'otherwise similar to thedrive rod 16, is coupled to the wedge-and-shoe assembly to producereciprocation thereof in the housing. The drive rod 76 has a flange 78welded thereto at 80, on which is seated a washer 82. The flange 78 andwasher 72, rather than being planar, have a concave generally sphericalcurvature, and the lower end 84 of the lower wedge 66 is sphericallyconvex to match. As seen by comparison of FIGS. 4 and 5, the lower wedge66 is thus efficiently isolated from all non vertical components ofmotion of the rod 76. Such components of motion arise from two sources.First, as earlier mentioned, although the motion of the pivot 18 at theouter end of the rod 16 (rod 76 in the improved embodiment) is generallylinear, it has an arcuate component about the pivot 22 as a center.Also, pivoting of the car truck with respect to the car body inherentlyproduces slight sidewise motion of the outer end of the rod withpractical constructions.

With the spherical-interface coupling between the rod 76 and the lowerwedge 66, a substantial angle of tilt of the rod in any direction withrespect to the housing of the energy-absorber produces no adverse effecton its proper operation. The radius of curvature of the sphericalinterface constituting, in essence, a ball-andsocket coupling betweenthe drive rod and the lower wedge, is substantially at the longitudinalcenter of the shoe, so that the aperture size in the wedges required toaccommodate the tilting of the rod is minimized. This predeterminationof the direction of tilt also permits the shaping of the apertures inthe wedges in a manner wherein the apertures are largest in crosssectionwhere the wedges are largest in cross-section.

Persons skilled in the art will readily devise many variantssubstantially departing from the illustrated embodiments, butnevertheless utilizing the teachings of the invention. The scope of theprotection to be afforded the invention should accordingly not belimited to the specific embodiments illustrated.

What is claimed is:

l. A motion-damping device for a railroad car having body and side-frameportions comprising an elongated housing adapted to be attached to oneof said portions and having a longitudinally extending internal frictionsurface, a friction shoe guided for sliding motion along said surfaceand having inclined wedging surfaces at opposite ends thereof, inner andouter wedge members having inclined surfaces mating with the respectiveinclined surfaces of the shoe, a drive actuator extending into thehousing and having its inner end inward of the inner wedge members, anabutment on the actuator engaging the outer wedge member in thedirection to drive it inwardly, a compression spring on the inner end ofthe actuator urging the inner wedge member outwardly to maintain aminimum friction, and a compression spring of greater capacity seated inthe inner end of the housing and also urging the inner wedge memberoutwardly to produce friction increasing with insertion of the actuatorand the shoe into the housing in response to external force and toreturn the actuator and.

the shoe outward when external force is withdrawn.

2. The motion-damping device of claim 1 having the wedge members ofgenerally square cross-section and having two shoes of L-shapecross-section.

3. The motion-damping device of claim 2 having additional mating wedgingsurfaces on the internal corners of the shoes and the diagonallyopposite external corners of the wedge members thereby engaged, thewedging surfaces at the corners being initially substantially the solepoints of contact between the wedging members and the shoes.

4. The motion-damping device of claim 1 having the abutment and theportion of the wedge member engaged thereby of mating generallyspherical shape.

5. The motion-damping device of claim 1 having a lever pivotally engagedwith the outer end of the actuator and adapted to slidingly engage theother portion of the car and a fulcrum member adapted to be mounted onthe same portion of the car as the housing and pivotally engaged withthe lever.

6 A motion-damping device for a railroad car having body and side-frameportions comprising a housing adapted to be mounted on one of saidportions, an actuating member extending from the housing, a leverpivotally engaged with the outer end of the actuator and adapted toslidingly engage the other said portion of the car, and a fulcrum memberadapted to be mounted on the same portion of the car as the housing andpivotally engaged with the lever, the housing containing friction meansopposing insertion of the actuating member and responsive to inwarddriven motion of the actuating member to increase the friction, springmeans to return the actuating member outwardly to follow the separatingrelative motion of said portions of the car produced by car-springoscillations, and means to maintain substantial friction opposing saidspring means to prevent following by the actuating member of the fastseparative and return relative motions of said portions of the carproduced by track discontinuities at crossings and the like.

7. The motion-damping device of claim 6 having a sliding assembly withinthe housing having an apertured outer member, the actuator memberextending through the outer member and having an abutment portionengaging the portion of the outer member surrounding the aperture, saidabutment portion and said surrounding portion being of mating sphericalshape.

1. A motion-damping device for a railroad car having body and side-frameportions comprising an elongated housing adapted to be attached to oneof said portions and having a longitudinally extending internal frictionsurface, a friction shoe guided for sliding motion along said surfaceand having inclined wedging surfaces at opposite ends thereof, inner andouter wedge members having inclined surfaces mating with the respectiveinclined surfaces of the shoe, a drive actuator extending into thehousing and having its inner end inward of the inner wedge members, anabutment on the actuator engaging the outer wedge member in thedirection to drive it inwardly, a compression spring on the inner end ofthe actuator urging the inner wedge member outwardly to maintain aminimum friction, and a compression spring of greater capacity seated inthe inner end of the housing and also urging the inner wedge memberoutwardly to produce friction increasing with insertion of the actuatorand the shoe into the housing in response to external force and toreturn the actuator and the shoe outward when external force iswithdrawn.
 2. The motion-damping device of claim 1 having the wedgemembers of generally square cross-section and having two shoes ofL-shape cross-section.
 3. The motion-damping device of claim 2 havingadditional mating wedging surfaces on the internal corners of the shoesand the diagonally opposite external corners of the wedge membersthereby engaged, the wedging surfaces at the corners being initiallysubstantially the sole points of contact between the wedging members andthe shoes.
 4. The motion-damping device of claim 1 having the abutmentand the portion of the wedge member engaged thereby of mating generallyspherical shape.
 5. The motion-damping device of claim 1 having a leverpivotally engaged with the outer end of the actuator and adapted toslidingly engage the other portion of the car and a fulcrum memberadapted to be mounted on the same portion of the car as the housing andpivotally engaged with the lever.
 6. A motion-damping device for arailroad car having body and side-frame portions comprising a housingadapted to be mounted on one of said portions, an actuating memberextending from the housing, a lever pivotally engaged with the outer endof the actuator and adapted to slidingly engage the other said portionof the car, and a fulcrum member adapted to be mounted on the sameportion of the car as the housing and pivotally engaged with the lever,the housing containing friction means opposing insertion of theactuating member and responsive to inward driven motion of the actuatingmember to increase the friction, spring means to return the actuatingmember outwardly to follow the separating relative motion of saidportions of the car produced by car-spring oscillations, and means tomaintain substantial friction opposing said spring means to preventfollowing by the actuating member of the fast separative and returnrelative motions of said portions of the car produced by trackdiscontinuities at crossings and the like.
 7. The motion-damping deviceof claim 6 having a sliding assembly within the housing having anapertured outer member, the actuator member extending through the outermember and having an abutment portion engaging the portion of the outermember surrounding the aperture, said abutment portion and saidsurrounding portion being of mating spherical sHape.